Large scale data centers are increasingly used for a wide variety of tasks associated with applications such as electronic mail and Web browsing. For example, software as a service (SaaS) includes Web-based e-mail services (e.g., the MICROSOFT® HOTMAIL® e-mail service) where a vendor typically hosts all of the program logic and data and provides end users with access to this data over the public Internet through a Web-based user interface. A single data center can house thousands of individual devices, usually in the form of rack mounted computers, which are often servers. Consequently, many now refer to large data centers as “server farms”. Various techniques described herein pertain to management of server farms.